In printshops employing primarily phototypesetting techniques, in contrast to the older, hot metal typesetting, the composition of printed pages of books, catalogues, newspapers and the like is controlled in what is referred to as a paste-up operation in which bits and pieces of text and illustrative material are organized and balanced in the manner desired in a printed page. It has been the practice to carry out this step by an individual pasting up of such bits and pieces on a suitable mounting member either by means of paste, glue or wax on the reverse side, or appropriately placed strips of transparent adhesive tape. The operation is inherently messy and time consuming when changes or repositioning of the bits and pieces becomes necessary. Furthermore, the bits and pieces of text and illustrative material, frequently only partially positioned, can easily be damaged during subsequent printshop operations, and the assemblage is poorly suited to extended storage. It is evident, therefore, that this widely used technique leaves much to be desired.